drupal-mcp

MCP server for Drupal sites via the core JSON:API. List, search, create, update, and delete nodes / taxonomy terms / users on any Drupal 10/11 site with the jsonapi module enabled.

Works two ways:

• Claude Code plugin — install via the lucaspretti-plugins marketplace and Claude prompts you for the env vars.

• Standalone MCP — node drupal-mcp.js with env vars set. Plug into Claude Desktop, Cline, or any other MCP-compatible client.

Why JSON:API and not the older Drupal MCP module?

The contrib drupal/mcp module currently has ~250 installs and is in flux ("merging with the MCP Server module"). JSON:API is in Drupal core, stable, and standard. This server is a thin wrapper around endpoints your site already exposes — no new module to maintain on the Drupal side.

Drupal-side setup (one-time)

Required modules

drush en jsonapi serialization basic_auth -y

• jsonapi — exposes /jsonapi/* endpoints. Core module.

• serialization — JSON:API dependency. Core module.

• basic_auth — required for Authorization: Basic header authentication. Core module, not enabled by default. Without it, only anonymous reads work; every write returns 401.

JSON:API writes

By default JSON:API is read-only. If you need create / update / delete, flip the switch:

drush config:set jsonapi.settings read_only false -y

Or in config/sync/jsonapi.settings.yml (CMI-managed sites):

read_only: false

Keep read_only: true for read-only deployments — the plugin still works for drupal_list_* / drupal_get_node / drupal_query_jsonapi.

Bot role + user

Two patterns, pick one based on how much you trust the bot:

A) Admin role (simplest, recommended for full-access bots). Setting is_admin: true bypasses every permission check, same as the default administrator role. The single setting + a strong password gates all access.

langcode: en
status: true
dependencies: {}
id: mcp_bot
label: 'MCP bot'
weight: 10
is_admin: true
permissions: {}

B) Scoped role (when you want explicit limits). List exactly the perms the bot may use. Note that administer nodes alone does not grant create / edit / delete on bundles — those need either bundle-specific perms ('create article content', 'delete any page content', etc.) or 'bypass node access'.

is_admin: false
permissions:
  - 'access content'
  - 'access user profiles'
  - 'bypass node access'        # or per-bundle perms
  - 'administer taxonomy'
  - 'view own unpublished content'

Then create the user:

drush user:create mcp_bot --password='<strong-pw>'
drush user:role:add mcp_bot mcp_bot

Store the password in your secrets manager.

Install (Claude Code plugin)

/plugin marketplace add lucaspretti/claude-plugins
/plugin install drupal-mcp@lucaspretti-plugins

Set these env vars (via shell, .env, or your secrets manager):

DRUPAL_BASE_URL=https://your-site.example.com
DRUPAL_USER=mcp_bot
DRUPAL_PASSWORD=••••••••

Install (standalone)

git clone https://github.com/lucaspretti/drupal-mcp.git
cd drupal-mcp
npm install
cp .env.example .env  # fill in
node drupal-mcp.js

In your MCP client config (Claude Desktop claude_desktop_config.json, Cline, etc.):

{
  "mcpServers": {
    "drupal": {
      "command": "node",
      "args": ["/absolute/path/to/drupal-mcp/drupal-mcp.js"],
      "env": {
        "DRUPAL_BASE_URL": "https://your-site.example.com",
        "DRUPAL_USER": "mcp_bot",
        "DRUPAL_PASSWORD": "••••••••"
      }
    }
  }
}

Tools

Filter shorthand: { field_category: '<uuid>' } → filter[field_category]=<uuid>. Use { field: { value, operator } } for non-equality operators.

CLI flags

Each env var has an equivalent flag, useful when running outside an .env-aware shell:

node drupal-mcp.js \
  --base-url=https://your-site.example.com \
  --user=mcp_bot \
  --password=•••• \
  --jsonapi-prefix=/jsonapi \
  --timeout=30000

node drupal-mcp.js --help for the full list.

Troubleshooting

Error: fetch failed (cause: getaddrinfo ENOTFOUND <host>${var_name})

Claude Code's ${VAR} interpolation in .mcp.json substitutes from process.env, not from the settings.json env block alone. When a referenced var is unset upstream, the literal string ${var_name} is passed to the spawned process and concatenated into the URL.

Fix: ensure every var in .mcp.json env is also set in ~/.claude/settings.json (env block) or your shell environment. Or remove optional vars from .mcp.json and rely on the script's defaults.

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '...zod-to-json-schema/dist/esm/index.js'

The @modelcontextprotocol/sdk postinstall race occasionally leaves zod-to-json-schema half-built. Reinstall:

cd ~/.claude/plugins/cache/<marketplace>/drupal-mcp/<version>
rm -rf node_modules package-lock.json && npm install

401 Unauthorized on every request

• The basic_auth core module is not enabled. drush en basic_auth -y.

• Or the password is wrong / the user is blocked.

403 Forbidden on a specific bundle

The bot role lacks the permission for that bundle. Either grant 'create <bundle> content' / 'edit any <bundle> content' / 'delete any <bundle> content' per bundle, or grant 'bypass node access' for blanket node access, or set is_admin: true on the role for full-trust service accounts.

Note that administer nodes alone is NOT enough — it grants the admin UI but not the per-content-type CRUD permissions.

405 Method Not Allowed on writes

jsonapi.settings.read_only is still true. See "JSON:API writes" above.

301 redirects to a language-prefixed URL

If the language module is enabled, /jsonapi/... redirects to /<langcode>/jsonapi/.... Node's fetch follows automatically; curl needs -L. Nothing to fix on the server side.

Authentication

The plugin currently uses HTTP Basic auth (basic_auth core module). This is the simplest path that works out of the box on any Drupal site.

For a small / single-tenant deployment with a dedicated bot user and HTTPS-only, Basic auth is acceptable. For production or multi-integration setups, OAuth2 via simple_oauth is the correct choice for service accounts:

OAuth2 support is planned as an opt-in mode (DRUPAL_AUTH_MODE=oauth + DRUPAL_OAUTH_CLIENT_ID / _SECRET / _TOKEN_URL). Until then, treat the bot password as you would any service-account credential: store it in a secrets manager, scope the role tightly, and rotate periodically.

Security notes

• HTTPS only. Basic auth means the bot password travels on every request — don't run against http://.

• The Drupal-side bot user's role is the security boundary. Keep it scoped to the bundles and operations you actually need.

• JSON:API respects field access, but not entity-access-bypass — be careful with admin-bypass perms on the bot role.

• .env is gitignored. Don't commit credentials.

License

MIT